Composite reinforcement

ABSTRACT

A composite reinforcement includes a first nonwoven mat. A laid scrim overlies the first nonwoven mat, the laid scrim including a first plurality of yarns substantially oriented in a first direction and a second plurality of yarns substantially oriented in a second direction different from the first direction. The second plurality of yarns includes at least one different material from the first plurality of yarns and each of the yarns in the second plurality of yarns includes a tension greater than a tension of each of the yarns in the first plurality of yarns. A second nonwoven mat overlies the laid scrim, and a binder laminates the first nonwoven mat, the laid scrim, and the second nonwoven mat together to form the composite reinforcement.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. §119(e) to U.S.Provisional App. No. 62/094,351, entitled “COMPOSITE REINFORCEMENT”, byFabien Marc Pesquet et al., filed Dec. 19, 2014, which is assigned tothe current assignee hereof and incorporated herein by reference in itsentirety.

FIELD OF THE DISCLOSURE

The present disclosure relates to composite reinforcements for a varietyof structural and industrial purposes, including reinforcements forbuilding and roofing applications.

BACKGROUND

Roofing membranes include reinforcements meant to strengthen and extendthe life of the membrane. However, commercially-available reinforcementsfor roofing membranes are prone to “mole running,” or installationdefects caused by dimensional expansion along the length of thereinforcement, when the reinforcement is exposed to certainenvironmental conditions on the roof. This dimensional expansion cancause deformation of the reinforcement at one or more points where theroofing membrane is weakly adhered to the roof, leading to “mole runs”(e.g., ridges) in a direction perpendicular to the surface of the roof.Accordingly, a need continues to exist in the art for reinforcementsthat can meet new and sometimes demanding applications, includingroofing reinforcements that are resistant to deformation in response tochanging environmental conditions.

SUMMARY

In an embodiment, a composite reinforcement includes a first nonwovenmat, a laid scrim overlying the first nonwoven mat, where the laid scrimincludes a first plurality of yarns substantially oriented in a firstdirection and a second plurality of yarns substantially oriented in asecond direction different from the first direction, where the secondplurality of yarns includes at least one different material from thefirst plurality of yarns and where each of the yarns in the secondplurality of yarns includes a tension greater than a tension of each ofthe yarns in the first plurality of yarns, a second nonwoven matoverlying the laid scrim, and a binder laminating the first nonwovenmat, the laid scrim, and the second nonwoven mat together to form thecomposite reinforcement.

In another embodiment, a roofing membrane includes a compositereinforcement impregnated with an asphaltic composition, where thecomposite reinforcement includes a first nonwoven mat, a laid scrimoverlying the first nonwoven mat, where the laid scrim includes a firstplurality of yarns substantially oriented in a first direction and asecond plurality of yarns substantially oriented in a second directiondifferent from the first direction, where the second plurality of yarnsincludes at least one different material from the first plurality ofyarns and where each of the yarns in the second plurality of yarnsincludes a tension greater than a tension of each of the yarns in thefirst plurality of yarns, a second nonwoven mat overlying the laidscrim, and a binder laminating the first nonwoven mat, the laid scrim,and the second nonwoven mat together to form the compositereinforcement.

In yet another embodiment, a composite reinforcement is configured forincorporation into a roofing membrane, where the composite reinforcementincludes a polyester nonwoven mat, a laid scrim overlying the polyesternonwoven mat, where the laid scrim includes a plurality of fiberglassyarns oriented in a cross direction of the laid scrim and a plurality ofpolyester yarns and fiberglass yarns oriented in a main direction of thelaid scrim, and where each of the polyester yarns and fiberglass yarnsoriented in the main direction includes a tension greater than a tensionof each of the fiberglass yarns oriented in the cross direction, afiberglass nonwoven mat overlying the laid scrim, and a binderlaminating the polyester nonwoven mat, the laid scrim, and thefiberglass nonwoven mat together to form the composite reinforcement.

In a further embodiment, a method of forming a composite reinforcementincludes coating a laid scrim with a binder, where the laid scrimincludes a first plurality of yarns substantially oriented in a firstdirection and a second plurality of yarns substantially oriented in asecond direction different from the first direction, where the secondplurality of yarns includes at least one different material from thefirst plurality of yarns and where each of the yarns in the secondplurality of yarns includes a tension greater than a tension of each ofthe yarns in the first plurality of yarns, contacting the laid scrimwith a first nonwoven mat and a second nonwoven mat, where the laidscrim overlies the first nonwoven mat and where the second nonwoven matoverlies the laid scrim; and curing the binder to form the compositereinforcement.

In still another embodiment, a method of preventing a distortion on aroofing surface includes applying a roofing membrane to the roofingsurface, the roofing membrane including a composite reinforcement, wherethe composite reinforcement includes: a first nonwoven mat, a laid scrimoverlying the first nonwoven mat, where the laid scrim includes a firstplurality of yarns substantially oriented in a first direction and asecond plurality of yarns substantially oriented in a second directiondifferent from the first direction, where the second plurality of yarnsincludes at least one different material from the first plurality ofyarns and where each of the yarns in the second plurality of yarnsincludes a tension greater than a tension of each of the yarns in thefirst plurality of yarns, a second nonwoven mat overlying the laidscrim, and a binder laminating the first nonwoven mat, the laid scrim,and the second nonwoven mat together to form the compositereinforcement, exposing the roofing membrane to an environmentalcondition, relieving the tension of at least some of the yarns in thesecond plurality of yarns in response to the environmental condition;and preventing the distortion on the roofing surface.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are illustrated by way of example and are not limited in theaccompanying figures.

FIG. 1 depicts a composite reinforcement in accordance with anembodiment described herein.

FIGS. 2A-2B depict a laid scrim in accordance with an embodimentdescribed herein.

FIG. 3 depicts a method of applying tension to, and relieving tensionfrom, a yarn in accordance with an embodiment described herein.

FIG. 4 depicts a cross-sectional image of a composite reinforcement inaccordance with an embodiment described herein.

FIG. 5 depicts a graph of composite reinforcement displacement inaccordance with an embodiment described herein.

FIG. 6 depicts a graph of composite reinforcement air permeability inaccordance with an embodiment described herein.

Skilled artisans appreciate that elements in the figures are illustratedfor simplicity and clarity and have not necessarily been drawn to scale.For example, the dimensions of some of the elements in the figures maybe exaggerated relative to other elements to help to improveunderstanding of embodiments of the invention.

DETAILED DESCRIPTION

The following description in combination with the figures is provided toassist in understanding the teachings disclosed herein. The followingdiscussion will focus on specific implementations and embodiments of theteachings. This focus is provided to assist in describing the teachingsand should not be interpreted as a limitation on the scope orapplicability of the teachings. However, other teachings can certainlybe used in this application.

Before addressing details of the embodiments described below, some termsand phrases are defined or clarified. The term “filament” is intended tomean an elongated structure of any suitable length and material. Theterm “fiber” is intended to include a filament or filaments of anysuitable fabric or tissue, material, or substance. A “fiber” can includeboth cut filaments and continuous filaments. The term “yarn” is intendedto mean any ordered bundle of fibers, including a bundle of fibers thathas been spun, plied, braided, or otherwise assembled in an orderedfashion. The term “mat” is intended to mean any suitable nonwovenstructure containing filaments or fibers, including a randomizeddistribution of singular fibers. A “mat” may be formed by any suitablemeans, including by dry laid means, air laid means, meltblown means, orspunbond means. The term “scrim” is intended to mean any suitableassembly of yarns, including an ordered assembly of yarns, where theyarns may be oriented in one or more directions. The term “laid scrim”is intended to mean a nonwoven scrim. The term “composite” is intendedto refer to a structure with two or more distinct layers.

As used herein, the terms “comprises,” “comprising,” “includes,”“including,” “has,” “having” or any other variation thereof, areintended to cover a non-exclusive inclusion. For example, a method,article, or apparatus that comprises a list of features is notnecessarily limited only to those features but may include otherfeatures not expressly listed or inherent to such method, article, orapparatus. Further, unless expressly stated to the contrary, “or” refersto an inclusive-or and not to an exclusive-or. For example, a conditionA or B is satisfied by any one of the following: A is true (or present)and B is false (or not present), A is false (or not present) and B istrue (or present), and both A and B are true (or present).

Also, the use of “a” or “an” is employed to describe elements andcomponents described herein. This is done merely for convenience and togive a general sense of the scope of the invention. This descriptionshould be read to include one or at least one and the singular alsoincludes the plural, or vice versa, unless it is clear that it is meantotherwise. For example, when a single Embodiment is described herein,more than one Embodiment may be used in place of a single Embodiment.Similarly, where more than one Embodiment is described herein, a singleEmbodiment may be substituted for that more than one Embodiment.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. The materials, methods, andexamples are illustrative only and not intended to be limiting. To theextent not described herein, many details regarding specific materialsand processing acts are conventional and may be found in reference booksand other sources within the structural arts and correspondingmanufacturing arts.

The present invention provides for a composite reinforcement. In anembodiment, the composite reinforcement includes a first nonwoven matand a laid scrim overlying the first nonwoven mat, where the laid scrimincludes a first plurality of yarns substantially oriented in a firstdirection and a second plurality of yarns substantially oriented in asecond direction different from the first direction. The secondplurality of yarns includes at least one different material from thefirst plurality of yarns and each of the yarns in the second pluralityof yarns includes a tension greater than a tension of each of the yarnsin the first plurality of yarns. The composite reinforcement furtherincludes a second nonwoven mat overlying the laid scrim and a binderlaminating the first nonwoven mat, the laid scrim, and the secondnonwoven mat together to form the composite reinforcement.

The composite reinforcement as described herein is capable ofcounteracting the dimensional expansion experienced bycommercially-available reinforcements. For example, the compositereinforcement and, in particular, the scrim as described herein,includes shrinkable material which can shrink or contract in response toa change in environmental conditions, thereby balancing a tendency ofthe reinforcement to expand in response to the environmental conditionwith a contraction or shrinkage that will enable the reinforcement toresist deformation. In a roofing application, the ability of a portionof the reinforcement to contract or shrink can lead to the prevention ofundesirable ridges or “mole runs” in the reinforcement. The preventionof ridges, in turn, will desirably enable the roofing membrane to remainadhered to the roof surface as intended.

The composite reinforcement as described herein also is configured to becustomizable. In an embodiment, the amount of contraction or shrinkageof the shrinkable material within the reinforcement can be tailored orcustomized to particular requirements by adjusting the process by whichthe reinforcement is made, including the process by which certainprocess variables (e.g., tension, heat) are applied to the shrinkablematerial within the reinforcement. The reinforcement also can becustomized for particular applications, including applications that takeinto account the environmental conditions (e.g., temperatures) to whichthe reinforcement will be exposed in specific geographical areas.

The composite reinforcement as described herein also is configured toincrease certain physical attributes when incorporated into otherstructures. For example, when used to create a roofing membrane, thecomposite reinforcement described herein is intended to increase (a) thepeel strength of the roofing membrane from the roof surface; and (b) theasphaltic permeation of the composite reinforcement. With respect topeel strength, the peel strength between the layers of the compositereinforcement can be tailored depending on whether an unsaturatedcoating technique or a saturated coating technique, each as describedherein, is used. In an embodiment, the peel strength between the layerscan be increased using an unsaturated coating technique. Also withrespect to peel strength, the manner and location(s) in which a binderis distributed within one or more layers of the composite reinforcementcan maximize the air permeability of that layer, which in turn leads toan increased ability to permeate the reinforcement with asphalt. As aresult, the distribution of a binder within one or more layers mayimpact the delamination of the asphalt from the layer(s) and/or mayimpact the delamination of one or more layers from other layers withinthe reinforcement (e.g., a mat layer from a scrim layer).

The composite reinforcement includes a first nonwoven mat. The firstnonwoven mat can be made of any suitable organic or inorganic material,including any material suitable for use in a roofing membrane. In anembodiment, the first nonwoven mat is made of at least one suitablethermoset or thermoplastic polymeric material, or a blend of suitablepolymeric materials. For example, the first nonwoven mat can include apolyester, such as polyethylene terephthalate (PET). In a particularembodiment, the first nonwoven mat can consist essentially of apolyester. In another embodiment, the first nonwoven mat can incorporatemulticompound fibers, or fibers that have been extruded with differentmaterials in the core and shell/coating structures, respectively.

The first nonwoven mat can include any suitable structure orconfiguration. In an embodiment, the first nonwoven mat can include arandomized distribution of singular fibers. The fiber weight can includesuitable fiber weights between 0.5 denier and 5 denier, such asapproximately 1.5 denier. In a particular embodiment, the first nonwovenmat can include a multifilament carded web. The first nonwoven mat alsocan include any suitable dimensions, including those standard industrialdimensions established by the mat supplier, who can supply the mat inthe form of a rolled good. For example, the first nonwoven mat caninclude a thickness of between about 1 mil and about 10 mils, such as 5mils or 7 mils. The first nonwoven mat also can include any suitablelength. In an embodiment, the length of the first nonwoven mat cancorrespond to a length of a standardized roofing membrane, such as alength of approximately 72 feet. The first nonwoven mat further caninclude any suitable width. In an embodiment, the width of the firstnonwoven mat can correspond to a width of a standardized roofingmembrane, such as a width of approximately 36 inches. The first nonwovenmat can include any other suitable dimensions or physical properties,including a basis weight of between approximately 0.5 oz/yd² andapproximately 2 oz/yd². In an embodiment, the first nonwoven mat caninclude a tensile strength of between approximately 75 lbs/inch andapproximately 1200 lbs/inch. As discussed herein, the first nonwovenmat, as one layer of the composite reinforcement, can include a peelstrength. In an embodiment, the peel strength of the first nonwoven matfrom the other layers of a composite reinforcement formed using anunsaturated coating technique, can include a peel strength betweenapproximately 1 lb/inch of width of the mat and approximately 6 lbs/inchof width of the mat.

The composite reinforcement also includes a second nonwoven mat, whichcan be the same as the first nonwoven mat or can differ from the firstnonwoven mat in dimension(s), type of material, or any other suitablerespect. The second nonwoven mat can be made of any suitable organic orinorganic material, including any material suitable for use in a roofingmembrane. In an embodiment, the second nonwoven mat is made of at leastone suitable fiberglass material, including any suitablealkali-resistant glass, C-glass, or E-glass, a basalt material, a carbonmaterial, a metal material, a ceramic material, or a combinationthereof. In a particular embodiment, the second nonwoven mat can consistessentially of fiberglass fibers.

Like the first nonwoven mat, the second nonwoven mat can include anysuitable structure or configuration. In an embodiment, the secondnonwoven mat can include a distribution of randomly oriented fibers. Thesecond nonwoven mat also can include any suitable dimensions, includingdimensions that are the same as or different from those of the firstnonwoven mat. For example, the second nonwoven mat can include athickness of between about 10 mils and about 20 mils, such as betweenabout 15 mils and 18 mils. The second nonwoven mat also can include anysuitable length. In an embodiment, the length of the second nonwoven matcan correspond to a length of a standardized roofing membrane, such as alength of approximately 72 feet. The second nonwoven mat further caninclude any suitable width. In an embodiment, the width of the secondnonwoven mat can correspond to a width of a standardized roofingmembrane, such as a width of approximately 36 inches. The secondnonwoven mat can include any other suitable dimensions, including abasis weight of between approximately 0.5 lbs/100 ft² and approximately2.0 lbs/100 ft², such as between approximately 0.7 lbs/100 ft² andapproximately 0.9 lbs/100 ft².

Within the composite reinforcement, the first and second nonwoven matsmay or may not be in contact with each other along one or more suitablesurfaces. In an embodiment, the first and second nonwoven mats are notin contact with each other along any minor or major surface of eithermat, being separated by at least one intervening layer within thecomposite reinforcement. Furthermore, it will be understood that whilethe composite reinforcement has been described in terms of having twononwoven mats, the composite reinforcement can include any suitablenumber of nonwoven mats arranged relative to one another and to thecomposite reinforcement in any suitable orientation, each of which maybe the same as or different from the mats described herein. In addition,the orientation of the first and second nonwoven mats relative to oneother and relative to the composite reinforcement can include anysuitable orientation. In an embodiment, the first nonwoven mat can beconfigured such that it is oriented or positioned “below” or“underneath” the second nonwoven mat within the composite reinforcementwhile the second nonwoven mat can be configured such that it is orientedor positioned “above” the first nonwoven mat.

The composite reinforcement further includes a scrim. In a particularembodiment, the scrim includes a laid scrim. The scrim is configured tobe oriented or positioned in any suitable location relative to thecomposite reinforcement and each of the first and second nonwoven mats.For example, the scrim can be positioned or “sandwiched” between thefirst and second nonwoven mats such that the scrim is in partial or fullcontact with at least one of the first and second nonwoven mats (e.g.,at least a portion of a surface of the scrim contacts at least a portionof a surface of at least one of the first and second nonwoven mats). Thescrim includes any suitable dimensions, including dimensions that arethe same as or different from those of any of the other layers withinthe composite reinforcement. For example, the scrim can include athickness of between about 12 mil and about 70 mil. The scrim also caninclude any suitable length, including a length of a standardizedroofing membrane and/or a length of either of the first and secondnonwoven mats, such as a length of approximately 72 feet. The scrimfurther can include any suitable width, including a width of astandardized roofing membrane and/or a width of either of the first andsecond nonwoven mats, such as a width of approximately 36 inches.

The scrim includes yarns. In an embodiment, the scrim includes a firstplurality of yarns and a second plurality of yarns. Each plurality ofyarns includes a random or ordered assembly of one or more yarns. Thesecond plurality of yarns includes yarns that can be the same as ordifferent from the yarns in the first plurality of yarns. In anembodiment, at least some of the yarns in the second plurality of yarnsare different from the first plurality of yarns in any suitable manner.For example, the second plurality of yarns can include yarns of adifferent quantity, spacing, type, configuration, dimension,arrangement, material (e.g., composition or substance), or combinationthereof, from the first plurality of yarns. In a particular embodiment,the second plurality of yarns includes yarns with at least one differentmaterial from the yarns in the first plurality of yarns. Although thescrim is described herein in terms of a first plurality of yarns and asecond plurality of yarns, it will be understood that the scrim caninclude any suitable number or pluralities of yarns as desired,including a third plurality of yarns that may be the same as, ordifferent from, either or both of the first and second pluralities ofyarns.

The yarns of the scrim can include any suitable organic or inorganicmaterial, including any material suitable for use in a roofing membrane.In particular, the yarns of the scrim can include shrinkable materialwhich can shrink or contract. In an embodiment, the first plurality ofyarns includes fiberglass yarns, namely yarns made at least partly of orentirely of a suitable fiberglass material, including any suitablealkali-resistant glass, C-glass, or E-glass. The fiberglass yarns caninclude a sizing. In a particular embodiment, the first plurality ofyarns consists essentially of fiberglass yarns. The second plurality ofyarns can also include fiberglass yarns, either yarns made at leastpartly of or entirely of the same fiberglass material as the yarns ofthe first plurality, or yarns made at least partly of or entirely of adifferent fiberglass material than the yarns of the first plurality.These fiberglass yarns can include any suitable yarn weight, such as ayarn weight between approximately 330 dtex and approximately 2,750 dtex.

The second plurality of yarns further can include yarns of at least onedifferent material from the yarns in the first plurality of yarns. Forexample, the second plurality of yarns also can include yarns made atleast partly of or entirely of any suitable organic material, such asany suitable thermoset or thermoplastic polymeric material. Thesepolymeric yarns can include any suitable yarn weight, such as a yarnweight between approximately 200 denier and approximately 1,500 denier.In an embodiment, the polymeric material includes the shrinkablematerial such as polyester, including lower shrinkage polyester yarnsand higher shrinkage polyester yarns, polyamide (nylon), rayon, or acombination thereof. In a particular embodiment, the polymeric materialcan include polyethylene terephthalate (PET). In a particularembodiment, the second plurality of yarns can consist essentially ofpolyester yarns. In another particular embodiment, the second pluralityof yarns can consist essentially of lower shrinkage polyester yarns. Instill another particular embodiment, the second plurality of yarns canconsist essentially of higher shrinkage polyester yarns. A lowershrinkage yarn can include a yarn that is configured to shrink less than3% along a given dimension, while a higher shrinkage yarn can include ayarn that is configured to shrink greater than 3% along a givendimension, according to ASTM D-2259. In addition, the second pluralityof yarns can include any suitable ratio of yarns of different materials(e.g., blends of different yarns). For example, the second plurality ofyarns can include at least 1% polyester yarns, such as at least 5%, atleast 10%, at least 25%, at least 50%, at least 60%, at least 70%, atleast 75%, at least 80%, or even at least 85% polyester yarns. Thesecond plurality of yarns also can include less than 99% fiberglassyarns, such as less than 95%, less than 90%, less than 75%, less than50%, less than 40%, less than 30%, less than 25%, less than 20%, or evenless than 15% fiberglass yarns.

The yarns of the scrim can be oriented or positioned in any suitabledirection. For example, the first plurality of yarns can besubstantially oriented in a first direction (e.g., a first direction ofthe scrim) and the second plurality of yarns can be substantiallyoriented in a second direction (e.g., a second direction of the scrim).In an embodiment, the second direction is different from the firstdirection. In another embodiment, the second direction is substantiallythe same as the first direction. By “substantially oriented,” it ismeant that at least 50%, such as at least 60%, at least 70%, at least75%, at least 80%, at least 90%, or even at least 95% of the yarnswithin a given plurality of yarns is oriented in a given direction. Itwill be understood that a suitable direction can be described in termsof a direction, axis, or dimension of the scrim itself. In anembodiment, the first direction can include, correspond to, or beparallel to a cross, or weft, direction of the scrim. The crossdirection of the scrim can include a direction that is parallel to awidth of the scrim. The second direction can include, correspond to, orbe parallel to a main, machine, or warp direction of the scrim. The maindirection of the scrim can include a direction that is parallel to alength of the scrim. The first and second directions also can beoriented at any suitable angle with respect to each other. In aparticular embodiment, the first direction can be substantiallyperpendicular to or substantially orthogonal to the second direction.For example, the scrim can include a 0/90 scrim where the firstdirection is substantially perpendicular to the second direction and thefirst plurality of yarns are substantially oriented perpendicular to thesecond plurality of yarns.

Within a given plurality of yarns, the yarns can be oriented relative toone another in any suitable manner. For example, within a plurality ofyarns, the yarns can be substantially oriented parallel to one another.The yarns also can be positioned at any suitable distance from oneanother. In an embodiment, the yarns within a plurality of yarns can beat least partially in contact with one another. In another embodiment,the yarns can be spaced apart from one another, expressed in units ofyarns per inch. For example, in a given direction, the yarn spacing caninclude at least about 12 yarns per inch, such as at least about 9 yarnsper inch, at least about 8 yarns per inch, at least about 7.5 yarns perinch, at least about 6 yarns per inch, at least about 5.5 yarns perinch, at least about 5 yarns per inch, at least about 4 yarns per inch,or even at least about 1 yarn per inch. In a particular embodiment, thefirst plurality of yarns can include yarns spaced between about 1 yarnper inch and about 12 yarns per inch, such as at least 5.5 yarns perinch in the first direction. The second plurality of yarns can includeyarns spaced between about 1 yarn per inch and about 12 yarns per inch,such as at least 7.5 yarns per inch in the second direction. It will befurther understood that, because a given plurality of yarns can includeyarns of more than one material, the spacing of the yarns can alsoincorporate any suitable pattern of yarns of different materials. Forexample, within the second plurality of yarns, the yarns can be orientedsuch that one or more yarns of a first material (e.g., polyester) areinterspersed or alternated with one or more yarns of a second material(e.g., fiberglass). In an embodiment, one or more polyester yarns can beinterspersed between one or more fiberglass yarns. In a particularembodiment, the second plurality of yarns can be spaced at approximately7.5 yarns per inch in the second direction, which spacing can include apattern of approximately five fiberglass yarns and 2.5 polyester yarnsper inch.

Between separate pluralities of yarns, the yarns can be positionedrelative to one another in any suitable manner. If the scrim is woven,the yarns of the first plurality of yarns can be interwoven with theyarns of the second plurality of yarns. In an embodiment, the scrimincludes a laid scrim and the yarns of the first plurality of yarns canbe laid on top of, below, or in between at least some of the yarns ofthe second plurality of yarns. In a particular embodiment, the yarns ofthe first plurality of yarns are laid between the yarns of the secondplurality of yarns such that some of the yarns of the second pluralityare positioned above the yarns of the first plurality, while other yarnsof the second plurality are positioned below the yarns of the firstplurality. The yarns of the first plurality of yarns can even be laidbetween yarns of different material of the second plurality of yarns.For example, the first plurality of yarns can be laid on top of yarns ofa first material (e.g., polyester yarns) and laid below yarns of asecond material (e.g., fiberglass yarns) from the second plurality ofyarns.

Within the scrim, at least some of the yarns can include a tension. By“tension,” it is meant that a yarn can be subjected to, placed under, orhave applied to it, an external force which results in the yarn having ameasurable tension on it. It will be understood, however, that where oneor more yarns are described as having a tension, that tension also caninclude a zero value or no tension.

The external force can be applied to the yarn at any suitable time or byany suitable means during the manufacture of the yarn and/or the scrim,and the yarn can include a tension or remain tensioned in the finishedscrim. The tension can be measured and expressed in any suitable unitsof force per unit of linear density of the yarn. In an embodiment, theunits of tension include Newtons per tex (e.g., N/tex or cN/tex). Incertain instances, the tension also can be expressed as a function ofthe amount of binder present on or picked up by a given yarn, whichbinder is described in more detail herein.

Each of the yarns within the scrim can include any suitable tension. Inan embodiment, each of the yarns in the scrim can include a tensionbetween about 0 cN/tex and about 18 cN/tex. For example, at least one ofthe yarns in the first plurality of yarns can include a tension of about0 cN/tex. In a particular embodiment, each of the yarns in the firstplurality of yarns includes a tension of about 0 cN/tex. Yarns within agiven plurality of yarns can include the same tension as, or a different(e.g., greater or lesser) tension from, yarns within another pluralityof yarns. For example, at least some of the yarns of the secondplurality of yarns can include a tension greater than or lesser thanthat of the yarns of the first plurality of yarns. In a particularembodiment, each of the yarns in the second plurality of yarns includesa tension greater than a tension of each of the yarns in the firstplurality of yarns.

Different yarns within a given plurality of yarns also can includedifferent tensions. For example, different yarns within the secondplurality of yarns can include different tensions. In an embodiment,each of the yarns within the second plurality of yarns can include atension between about 1.0 cN/tex and about 18 cN/tex. Furthermore,different yarns made of different materials within a given plurality ofyarns can include different tensions. In a particular embodiment, one ormore yarns of a first material (e.g., polyester yarns) in the secondplurality of yarns can include a different tension from, such as agreater tension than, one or more yarns of a second material (e.g.,fiberglass yarns) in the second plurality of yarns. For example, eachpolyester yarn can include a tension of between about 7.2 cN/tex andabout 10.8 cN/tex. Each fiberglass yarn can include a tension of betweenabout 2.2 cN/tex and about 6.6 cN/tex.

The composite reinforcement further includes a binder or bindercomposition. The binder includes any suitable organic resin. The organicresin can include one or more suitable polymers, one or more suitablecopolymers, a suitable blend, or combination thereof. In an embodiment,the organic resin includes materials designed to withstand hot asphaltcoating during the roofing membrane-making process. For example, theorganic resin is a thermosetting resin. The binder also includes anysuitable composition sufficient to laminate together the first nonwovenmat, the scrim, and the second nonwoven mat to form the compositereinforcement. In one embodiment, the binder includes an acrylic oracrylate. In another embodiment, the binder includes a polyvinylalcohol. In yet another embodiment, the binder includes a styrenebutadiene rubber composition. The styrene butadiene rubber compositioncan be cross-linked styrene butadiene rubber, including between about30% to about 80% styrene, such as about 45% to about 75% styrene, suchas about 50% to about 70% styrene, such as about 55% styrene. The binderalso can include any suitable additive or filler to provide advantageousproperties to the binder, the composite reinforcement, and/or any of itslayers.

The binder can be present within each layer of the compositereinforcement, but may or may not be present throughout the entirety ofeach layer. In an embodiment, the binder can penetrate through theentirety of (e.g., saturate) the scrim and one or more of the first andsecond nonwoven mats. For example, the binder can penetrate through theentirety of the scrim and the second nonwoven mat (e.g., the fiberglassmat). In another embodiment, the binder can penetrate through theentirety of (e.g., saturate) the scrim, but the binder may onlypenetrate a portion of either of the first or second nonwoven matswithout saturating either mat or penetrating through the entirety ofeither mat.

The binder also can be present at any suitable concentration within thecomposite reinforcement, and different layers of the reinforcement caninclude different concentrations of the binder. For example, the scrimcan include a greater concentration of binder than either of the firstor second nonwoven mats. The binder can further be present at varyingconcentrations within a given layer. As noted herein, the binder can bepresent at a given concentration in a portion of either of the first orsecond nonwoven mats, but may not be present at any concentration inanother portion of the same mat. In another embodiment, different yarnswithin the scrim can include different concentrations of the binder. Forexample, where the second plurality of yarns includes yarns of differentmaterials, such as both polyester yarns and fiberglass yarns, each ofthe polyester yarns can include a greater concentration of binder on itthan each of the fiberglass yarns. Where the first plurality of yarnsalso includes fiberglass yarns, each of the fiberglass yarns of thefirst plurality of yarns can include a greater concentration of binderon it than each of the fiberglass yarns within the second plurality ofyarns.

The concentration of binder on or within a given layer of the compositereinforcement can be expressed in any suitable manner, including as apercentage of dry coating per unit (DPU). The DPU percentage reflectsthe ratio of the weight of dried or cured binder present in a givenlayer to the weight of the layer itself. For example, a 100% DPUindicates that the weight of the dried or cured binder present in alayer (e.g., the scrim) is equal to the weight of the layer itself. Inan embodiment, the concentration of binder on the scrim can include aDPU percentage between about 50% and about 150% DPU.

The composite reinforcement can be formed in any suitable manner. In anembodiment, the first nonwoven mat, the second nonwoven mat, and thescrim are formed first. Each of the mats can be produced by any of themeans disclosed herein. The scrim can be formed by any suitable woven ornonwoven means. In a particular embodiment, the scrim includes a laidscrim, in which the first and second pluralities of yarns are laid in adesired nonwoven configuration or arrangement to form the scrim. Priorto formation of the scrim, or concurrently with the formation of thescrim, one or more external forces can be applied to at least some ofthe yarns in the scrim such that the finished scrim includes at leastsome yarns with a tension. In an embodiment, the external force isapplied to at least some of the yarns in the main directionsimultaneously with the formation of the scrim.

Any method of providing the binder to any layer of the compositereinforcement is envisioned. For instance, the scrim then can be coatedwith the binder in any suitable manner, including by known dip coating,spray coating, and extrusion coating techniques. In an embodiment, thescrim can be coated with the binder while the binder is in a liquidstate. Excess amounts of the binder can be removed from the scrim usingany known technique. In an “unsaturated” method or technique, the scrimcan be coated as described to saturate or soak the scrim in the liquidbinder, but neither the first nonwoven mat nor the second nonwoven matmay be similarly coated (e.g., neither mat is coated concurrently withthe scrim). After the scrim has been coated with the liquid binder, thescrim can be contacted with or introduced to at least one of the firstnonwoven mat and the second nonwoven mat. For example, the scrim isbrought into contact with each of the first nonwoven mat and the secondnonwoven mat. Bringing these three layers into contact after the scrimhas been coated with the liquid binder permits at least some of theliquid binder to migrate from the scrim and penetrate at least a portionof each of the first and second nonwoven mats without saturating orfully penetrating either of the mats with the liquid binder. Forexample, when an unsaturated coating technique is used to form thecomposite reinforcement, the binder can penetrate less thanapproximately 50% of a thickness of the first nonwoven mat and less thanapproximately 33-35% of a thickness of the second nonwoven mat. In a“saturated” method or technique, both the scrim and at least one of thefirst and second nonwoven mats can be coated together with the binderwhile the binder is in a liquid state. For example, both the scrim andthe second nonwoven mat (e.g., the fiberglass mat) can be coated withthe liquid binder, which permits the liquid binder to saturate or fullypenetrate both the scrim and the second nonwoven mat. The third layer(e.g., the first nonwoven mat) is then brought into contact with theother layers, such that a portion of the liquid binder migrates from thescrim to penetrate at least a portion of the first nonwoven mat withoutsaturating the first nonwoven mat. When a saturated coating technique isused to form the composite reinforcement, the binder can penetrate lessthan 20% of a thickness of the first nonwoven mat, such that less binderpenetrates a thickness of the first nonwoven mat in the saturatedtechnique than in the unsaturated technique. Without wishing to bound bytheory, the unsaturated technique produces a composite reinforcementwith less binder present in both of the mat layers than the amount ofbinder present in both mat layers using the saturated technique. Lessbinder saturation of the mat layers can facilitate a greater saturationor penetration of those same layers by an asphaltic composition when thecomposite is used to make a roofing membrane. Greater saturation orpenetration of the mat layers by the asphaltic composition can lead togreater interlaminar strength within the reinforcement (e.g., lessdelamination between the layers of the composite reinforcement) andincreased peel strength of the resulting roofing membrane.

After the layers are brought into contact with one another, the bindercan be cured in any suitable manner to form the composite reinforcement.In an embodiment, the layers can be transported to an oven operating ata temperature sufficient to cure the binder. For example, the layers canreside in the oven for a suitable period of time, such as at leastthirty seconds, at least one minute, or at least 1.5 minutes. The ovencan include a temperature, or include internal devices (e.g.,steam-heated drying cans) at a temperature such as at least 250 degreesFahrenheit, or at least 300 degrees Fahrenheit. One effect of curing thebinder on the layers of the composite reinforcement is that, whereapplied, at least a portion of the tension on the yarns in the scrim isalso “heat set,” “memorized,” or “fixed,” such that when the compositereinforcement is removed from the oven and allowed to cool, the tensionof the yarns in the scrim is retained (e.g., is not relieved). Morespecifically, those yarns in the scrim that have a tension, by virtue ofhaving an external force applied when they enter the oven, also can havean internal stress due to the internal alignment of the molecular chainsor chain segments within the yarns. For example, the introduction of anexternal force (e.g., a weight) to a yarn in the scrim, can provide ameasureable tension to a yarn, can also lock in place the molecularstructure of that yarn such that the internal alignment of the molecularchains or chain segments within the yarn increases. The increasedinternal alignment of the molecular chains or chain segments within theyarn creates and/or increases an internal stress between the molecularchains. Both the tension of the yarn, caused by the application of anexternal force to the yarn, and the internal stress of the yarn, causedby the increased internal alignment of the molecular chains, can resultin a stretched or elongated yarn. When such a yarn is exposed to theheat source, some of the internal stress between the molecular chains orchain segments may be relaxed, but at least a portion of the yarnelongation (resulting from the chain alignment) and the tension of theyarn (from the application of the external force) are retained. Suchelongation is memorized or fixed as the yarn cools, and the yarn canretain the tensile force in the finished composite reinforcement untilexposed to a future heat source, such as, for example, the ambient heatfrom a roof. Once cooled, the composite reinforcement can be furtherprocessed, packaged, and transported for use as a structuralreinforcement. In an embodiment, the composite reinforcement can bepartially or fully impregnated with an asphaltic composition (e.g., anasphaltic/rubber composition) to form a roofing membrane for reinforcinga roof. It will be understood that the composite reinforcementsdescribed herein can be used to form a roofing membrane that meetsaccepted commercial standards for roofing membranes, such as theindustrial specifications set forth in ASTM D-6162.

As described herein, traditional commercially-available reinforcements,such as those installed in roofing membranes, are prone to “molerunning” or dimensional expansion along the length of the reinforcementwhen the roof, and the reinforcement, are exposed to certainenvironmental conditions (e.g., diurnal heating, sunshine, and/orelevated ambient temperatures). For example, a roof can include asurface temperature of about 40 degrees Fahrenheit in the morning, butthat same roof can achieve surface temperatures of at least 150 degreesFahrenheit, such as at least 175 degrees or even at least 180 degreesFahrenheit, in the same day. When the roof heats to such a degree, thedimensional expansion experienced by the reinforcement can causedeformation or distortion of the reinforcement at one or more pointswhere the roofing membrane is weakly adhered to the roof, leading toundesirable ridges (e.g., “mole runs”) in a direction perpendicular tothe surface of the roof.

The composite reinforcement described herein, particularly theshrinkable material within the composite reinforcement, can contract inresponse to a change in environmental conditions, thereby preventing orcounteracting any initial dimensional expansion that would lead to suchdistortion in the roofing membrane. In an embodiment, the compositereinforcement described herein can begin to exhibit such desirablecontraction when a roofing membrane in which the reinforcement isincorporated (and/or the itself) reaches a surface temperature of atleast 35 degrees Celsius. More specifically, the tensioned yarns of thescrim within the composite reinforcement include the internal stressthat is configured to be relieved. The tensioned yarns have built inthermal stress because of the forced alignment of the molecular chain orchain segments. When the tensioned yarns are exposed to a heat source(e.g., from diurnal warming of the reinforcement and/or the roofingmembrane on the surface of a roof), the internal stress on those yarnsis released as the aligned molecular chains within the yarns seek a moredisordered arrangement. This release of the internal stress causes theyarns to shrink, eliminating the elongation of the yarns and the tensionon the yarns. Such shrinkage is sufficient to overcome a tendency of theyarns within the scrim (and the composite reinforcement) to otherwiseexpand undesirably in response to the heat source. In an embodiment, thetension on certain of the yarns (e.g., the yarns made of the shrinkablematerial) in the scrim is configured to be relieved. In anotherembodiment, the tension of all of the yarns in the scrim is configuredto be relieved. In a particular embodiment, the tension of at least someof the yarns in the second plurality of yarns in the scrim is configuredto be relieved.

The tension can be relieved by any suitable means. For example, thetension is configured to be relieved by shrinkage of at least some ofthe yarns, including the yarns made of the shrinkable material. Theshrinkage can occur in a variety of suitable directions or dimensions,including in a direction parallel to a dimension of the yarn (e.g., awidth or length of the yarn) and/or a direction or dimension of thescrim. In a particular embodiment, shrinkage can occur along a length ofa yarn, which length can be parallel to the second direction describedherein, parallel to a main, machine, or warp direction of the scrim,and/or parallel to a length of the scrim.

The shrinkage of the yarns also can include any suitable dimensionalchange in the yarns, including a shortening of the yarns and, in someinstances, an increase in diameter of the yarns. In a particularembodiment, the shortening includes a shortening of a yarn along itslength. This shortening can be measured using any suitable method,including those methods set forth in commercially-available industrystandards such as ASTM D-2259. Each of the yarns whose tension isrelieved can include any suitable amount of shortening. In anembodiment, relieving the tension on a given yarn can shorten that yarnby between about 0.2% and about 15%, as compared to the length of theyarn before its tension was relieved (e.g., the length of the tensionedyarn in the finished composite reinforcement).

Turning to FIG. 1, a composite reinforcement is depicted in accordancewith an embodiment described herein. It will be understood that, whilethe composite reinforcement 100 is described in terms of three layers110, 120, and 130, the composite reinforcement 100 can include anysuitable number or combination of different layers. The compositereinforcement includes a first nonwoven mat 110, a second nonwoven mat120, and a scrim 130. In an embodiment, the first nonwoven mat 110includes polyester fibers or is a polyester mat. In a particularembodiment, the first nonwoven mat 110 consists essentially of polyesterfibers. The second nonwoven mat 120 can include fiberglass fibers or bea fiberglass mat. In a particular embodiment, the second nonwoven mat120 consists essentially of fiberglass fibers. A scrim 130 can besandwiched between, and separate, the first nonwoven mat 110 and thesecond nonwoven mat 120. The scrim 130 can include any suitable woven ornonwoven scrim and, in an embodiment, the scrim 130 includes a laidscrim 130.

Turning to FIG. 2A, the laid scrim 130 is depicted in accordance with anembodiment described herein. It will be understood that, while the laidscrim 130 is described and depicted in terms of two pluralities of yarns140 and 150, the laid scrim 130 can include any suitable number ofpluralities of yarns arranged in any suitable configuration. A firstplurality of yarns 140 can include any suitable number of yarns 141.Each yarn 141 can include any suitable material and be substantiallyoriented in any suitable direction. In an embodiment, the firstplurality of yarns 140 includes fiberglass yarns 141. In anotherembodiment, each yarn 141 includes fiberglass and, in a particularembodiment, each yarn 141 consists essentially of fiberglass. At leastsome of the yarns 141, or each of the yarns 141, can be substantiallyoriented in a first direction C. In an embodiment, the first direction Ccan be parallel to a cross or weft direction of the laid scrim 130. Theyarns 141 can further include any suitable spacing 145, expressed interms of yarns per inch. In an embodiment, the yarns 141 can include aspacing of between about 1 yarn per inch and about 12 yarns per inch,such as about 5.5 yarns per inch.

A second plurality of yarns 150 can include any suitable number of yarns151 and 153. Each yarn 151 and 153 can include any suitable material andbe substantially oriented in any suitable direction. In an embodiment,the second plurality of yarns 150 includes yarns of a first material andyarns of a second material. For example, the second plurality of yarns150 includes fiberglass yarns 151 and polyester yarns 153 (e.g., lowershrinkage polyester yarns 153 and/or higher shrinkage polyester yarns153). In a particular embodiment, each yarn 151 consists essentially offiberglass and each yarn 153 consists essentially of polyester. At leastsome of the yarns 151 and 153, or each of the yarns 151 and 153, can besubstantially oriented in a second direction M. In an embodiment, thesecond direction M can be parallel to a main, machine, or warp directionof the laid scrim 130. In a particular embodiment, the second directionM can be substantially perpendicular to the first direction C, and thelaid scrim 130 can include a 0/90 scrim. The yarns 151 and 153 canfurther include any suitable spacing 155, expressed in terms of yarnsper inch. In an embodiment, the yarns 151 and 153 can include a spacingof between about 1 yarn per inch and about 12 yarns per inch, such asabout 7.5 yarns per inch.

Turning to FIG. 2B, a cross-section of the laid scrim 130 of FIG. 2A,taken along the first direction C, is depicted in accordance with anembodiment described herein. The yarns 141, 151, and 153 of the firstand second pluralities of yarns 140 and 150 can be laid relative to oneanother in any suitable configuration or pattern. In an embodiment, theyarns 151 and 153 of the second plurality 150 can be laid in arepetitive pattern. For example, one yarn 153 can be laid in betweenfour yarns 151 (e.g., one yarn 153 is laid after two yarns 151 arelaid). Moreover, the yarns 141 can be laid between the yarns 151 and153. For example, as the laid scrim 130 is formed, the yarns 141 arelaid on top of the yarns 153, and the yarns 151 are laid on top of theyarns 141.

Turning to FIG. 3, a method of applying tension to, and relievingtension from, a yarn is depicted in accordance with an embodimentdescribed herein. A yarn, such as a yarn made of shrinkable material(e.g., a polyester yarn 153 from FIGS. 2A-B) can be provided forincorporation into a scrim, such as the laid scrim 130, with an originallength L. The yarn 153 may not include a tension, or any internalstress, at this stage. At step 310, a force 313 (e.g., an externalweight) is applied to the yarn 153, which elongates the yarn 153 to anew length P. In an embodiment, the force 313 can include a weightbetween about 800 grams and about 1200 grams. The application of theforce 313 to the yarn 153, and the elongation of the yarn 153 (whichmay, in part, result from the creation of, or an increase in, aninternal stress of the yarn 153), results in the yarn 153 having atension that can be expressed in any suitable units, such as units offorce per linear density of the yarn (e.g., N/tex or cN/tex). At step320, heat can be applied to the yarn 153, while the force 313 is stillbeing applied to the yarn 153, to “heat-set” or “memorize” theelongation of the yarn 153. In an embodiment, this heat can include theoven used to cure the binder on the layers of the compositereinforcement 100. As a result, the yarn 153 retains a tension and anelongated length (due, in part, to an internal stress on the yarn 153)after the heat is removed from the yarn 153. Each of the steps 310 and320 can be adjusted (e.g., by adjusting the amount of the force 313and/or the amount of heat applied to the yarn 153) to tailor the tensionincluded in the yarn 153, as well as to tailor the amount of shrinkage(i.e., due to release of an internal stress on the yarn 153) that theyarn 153 can undergo at a later time (e.g., during step 340). At step330, the force 313 can be removed from the yarn 153. When the force 313is removed, some of the elongation in the yarn 153 can be lost. One wayin which the elongation in the yarn 153 is lost is by partiallongitudinal shrinkage of the yarn 153 from the elongated length P to anew length N. Despite this partial shrinkage, however, tension remainsin the yarn 153, as also evidenced by the elongation of the yarn 153from its original length L to the new length N. It is this tension andelongated length N which are present in the yarn 153 when it isincorporated into the laid scrim 130.

Step 340 can occur at any suitable future time, including at a time whenthe laid scrim 130 (and the yarn 153) have been incorporated into thecomposite reinforcement 100 that, in turn, has been incorporated into aroofing membrane applied to a roof. During step 340, heat can be appliedagain to the yarn 153. For example, heat in the form of sunshine ordiurnal warming can be applied to the yarn 153. In response to theapplication of the heat, the yarn may experience an initial dimensionalexpansion, after which the tension on the yarn 153 can be relieved (dueto, for example, release of the internal stress in the yarn 153 whichcauses the yarn 153 to lose elongation), such that the yarn 153 canexperience a final shrinkage 350 to a shortened length S. In anembodiment, relieving the tension on the yarn 153 can shorten that yarnby between about 0.2% and about 15% between lengths N and S. The finalshrinkage 350 of the yarn 153 can include an initial shrinkage 360 fromthe original length L to the shortened length S, which can be the resultof the yarn 153 shrinking irrespective of any heat-setting stepperformed at step 320. The final shrinkage 350 also can include anextended shrinkage 370, from the length N to the original length L,which extended shrinkage 370 is the result of relieving the tension thatwas applied to the yarn 153 (e.g., via the force 313) and heat-setwithin the yarn 153 at steps 310 and 320. As a result, not only can theamount of tension applied to the yarn 153 be tailored at steps 310 and320, but the amount of future shrinkage experienced by the yarn 153 asthe tension on the yarn 153 is relieved also can be predicted andtailored. The ability to predict and tailor the future shrinkage of theyarn 153 also enables the laid scrim 130, and the compositereinforcement 100, to be specifically designed to counteract dimensionalexpansion, and deformation, in particular geographical settings orenvironmental conditions.

FIG. 4 depicts a cross-sectional image of the composite reinforcement100 in accordance with an embodiment described herein. Thecross-sectional image of the composite reinforcement 100 was obtainedusing computer tomography (CT) scanning and was taken along a lineparallel to the first direction C. A yarn 141 from the first pluralityof yarns 140 (e.g., a fiberglass weft yarn of the laid scrim 130) isdepicted by the white line or stripe shown across the center of FIG. 4.A cross-sectional image of a yarn 151 from the second plurality of yarns150 (e.g., a fiberglass warp yarn of the laid scrim 130) is depicted bythe white structure in the center of the image. Because inorganicmaterials appear more brightly, or with more contrast, than organicmaterials in an image made by CT scanning, the first nonwoven mat 110(e.g., a polyester mat) is not discernible in FIG. 4, but is positionedbelow the yarn 141. The second nonwoven mat 120 (e.g., a fiberglass mat)is depicted above the yarns 141 and 151, with the white flecks or spotsindicating the presence of inorganic material (e.g., fiberglass) in themat. A cross-sectional image of a yarn 153 (e.g., a polyester warp yarnof the laid scrim 130) also is not discernible in FIG. 4, but the yarnis positioned to the left of the yarn 151 and below the yarn 141, suchthat the yarn 141 is sandwiched between the yarns 151 and 153 in thelaid scrim 130. An organic binder (e.g., the binder 415) is present onand around the yarns 141, 151, and 153. Because an unsaturated techniquewas employed to coat the laid scrim 130, the binder 415 can saturate thelaid scrim 130, but may penetrate only a portion of each of the firstnonwoven mat 110 and the second nonwoven mat 120.

EMBODIMENTS Embodiment 1

A composite reinforcement including a first nonwoven mat, a laid scrimoverlying the first nonwoven mat, wherein the laid scrim includes afirst plurality of yarns substantially oriented in a first direction anda second plurality of yarns substantially oriented in a second directiondifferent from the first direction, wherein the second plurality ofyarns includes at least one different material from the first pluralityof yarns and wherein each of the yarns in the second plurality of yarnsincludes a tension greater than a tension of each of the yarns in thefirst plurality of yarns, a second nonwoven mat overlying the laidscrim, and a binder laminating the first nonwoven mat, the laid scrim,and the second nonwoven mat together to form the compositereinforcement.

Embodiment 2

A roofing membrane including a composite reinforcement impregnated withan asphaltic composition, wherein the composite reinforcement includes afirst nonwoven mat, a laid scrim overlying the first nonwoven mat, wherethe laid scrim includes a first plurality of yarns substantiallyoriented in a first direction and a second plurality of yarnssubstantially oriented in a second direction different from the firstdirection, where the second plurality of yarns includes at least onedifferent material from the first plurality of yarns and where each ofthe yarns in the second plurality of yarns includes a tension greaterthan a tension of each of the yarns in the first plurality of yarns, asecond nonwoven mat overlying the laid scrim, and a binder laminatingthe first nonwoven mat, the laid scrim, and the second nonwoven mattogether to form the composite reinforcement.

Embodiment 3

A composite reinforcement configured for incorporation into a roofingmembrane, wherein the composite reinforcement includes a polyesternonwoven mat, a laid scrim overlying the polyester nonwoven mat, whereinthe laid scrim includes a plurality of fiberglass yarns oriented in across direction of the laid scrim and a plurality of polyester yarns andfiberglass yarns oriented in a main direction of the laid scrim, andwherein each of the polyester yarns and fiberglass yarns oriented in themain direction includes a tension greater than a tension of each of thefiberglass yarns oriented in the cross direction, a fiberglass nonwovenmat overlying the laid scrim, and a binder laminating the polyesternonwoven mat, the laid scrim, and the fiberglass nonwoven mat togetherto form the composite reinforcement.

Embodiment 4

A method of forming a composite reinforcement, the method includingcoating a laid scrim with a binder, wherein the laid scrim includes afirst plurality of yarns substantially oriented in a first direction anda second plurality of yarns substantially oriented in a second directiondifferent from the first direction, wherein the second plurality ofyarns includes at least one different material from the first pluralityof yarns and wherein each of the yarns in the second plurality of yarnsincludes a tension greater than a tension of each of the yarns in thefirst plurality of yarns, contacting the laid scrim with a firstnonwoven mat and a second nonwoven mat, wherein the laid scrim overliesthe first nonwoven mat and wherein the second nonwoven mat overlies thelaid scrim; and curing the binder to form the composite reinforcement.

Embodiment 5

The composite reinforcement or method of any one of embodiments 1, 2,and 4, wherein the first nonwoven mat includes polyester fibers.

Embodiment 6

The composite reinforcement or method of any one of embodiments 1, 2,and 4, wherein the first nonwoven mat consists essentially of polyesterfibers.

Embodiment 7

The composite reinforcement of embodiment 3, wherein the polyesternonwoven mat consists essentially of polyester fibers.

Embodiment 8

The composite reinforcement or method of any one of embodiments 1, 2,and 4, wherein the second nonwoven mat includes fiberglass fibers.

Embodiment 9

The composite reinforcement or method of any one of embodiments 1, 2,and 4, wherein the second nonwoven mat consists essentially offiberglass fibers.

Embodiment 10

The composite reinforcement of embodiment 3, wherein the fiberglassnonwoven mat consists essentially of fiberglass fibers.

Embodiment 11

The composite reinforcement or method of any one of embodiments 1, 2,and 4, wherein the first plurality of yarns includes fiberglass yarns.

Embodiment 12

The composite reinforcement of any one of embodiments 1, 2, and 4,wherein the first plurality of yarns consists essentially of fiberglassyarns.

Embodiment 13

The composite reinforcement or method of any one of embodiments 1, 2,and 4, wherein the second plurality of yarns includes polyester yarnsand fiberglass yarns.

Embodiment 14

The composite reinforcement or method of any one of embodiments 1, 2,and 4, wherein the second plurality of yarns consists essentially ofpolyester yarns.

Embodiment 15

The composite reinforcement or method of any one of embodiments 1, 2,and 4, wherein the first direction is a cross direction of the laidscrim and the second direction is a main direction of the laid scrim,and wherein the first plurality of yarns is substantially oriented inthe cross direction and wherein the second plurality of yarns issubstantially oriented in the main direction.

Embodiment 16

The composite reinforcement or method of embodiment 15, wherein thecross direction includes between about 1 yarn per inch and about 12yarns per inch, and wherein the main direction includes between about 1yarn per inch and about 12 yarns per inch.

Embodiment 17

The composite reinforcement of embodiment 15, wherein the firstplurality of yarns includes fiberglass yarns and wherein the secondplurality of yarns includes polyester yarns and fiberglass yarns.

Embodiment 18

The composite reinforcement of embodiment 15, wherein the firstplurality of yarns consists essentially of fiberglass yarns and whereinthe second plurality of yarns consists essentially of polyester yarns.

Embodiment 19

The composite reinforcement or method of any one of embodiments 1, 2, 3,and 4, wherein the binder includes styrene-butadiene rubber.

Embodiment 20

The composite reinforcement or method of any one of embodiments 1, 2,and 4, wherein the binder penetrates at least a portion of the secondnonwoven mat without saturating the second nonwoven mat.

Embodiment 21

The composite reinforcement of embodiment 3, wherein the binderpenetrates at least a portion of the fiberglass nonwoven mat withoutsaturating the fiberglass nonwoven mat.

Embodiment 22

The composite reinforcement or method of any one of embodiments 1, 2,and 4, wherein the laid scrim includes a greater concentration of binderthan the first nonwoven mat or the second nonwoven mat.

Embodiment 23

The composite reinforcement of embodiment 3, wherein the laid scrimincludes a greater concentration of binder than the polyester nonwovenmat or the fiberglass nonwoven mat.

Embodiment 24

The composite reinforcement or method of any one of embodiments 1, 2,and 4, wherein the second plurality of yarns includes a first yarn and asecond yarn, and wherein the first yarn includes a greater concentrationof binder than the second yarn.

Embodiment 25

The composite reinforcement or method of embodiment 24, wherein thefirst plurality of yarns includes a third yarn, and wherein the thirdyarn includes a greater concentration of binder than the second yarn.

Embodiment 26

The composite reinforcement of embodiment 3, wherein a polyester yarnfrom the plurality of polyester yarns and fiberglass yarns oriented inthe main direction includes a greater concentration of binder than afiberglass yarn from the plurality of polyester yarns and fiberglassyarns.

Embodiment 27

The composite reinforcement of embodiment 26, wherein a fiberglass yarnfrom the plurality of fiberglass yarns oriented in the cross directionincludes a greater concentration of binder than the fiberglass yarn fromthe plurality of polyester yarns and fiberglass yarns oriented in themain direction.

Embodiment 28

The composite reinforcement or method of any one of embodiments 1, 2,and 4, wherein the tension of each of the yarns of the second pluralityof yarns includes a tension between about 1.0 cN/tex and about 18cN/tex.

Embodiment 29

The composite reinforcement of embodiment 24, wherein a tension of thefirst yarn is greater than a tension of the second yarn.

Embodiment 30

The composite reinforcement of embodiment 26, wherein a tension of thepolyester yarn is greater than a tension of the fiberglass yarn.

Embodiment 31

The composite reinforcement of any one of embodiments 1, 2, and 4,wherein the tension of each of the yarns of the first plurality of yarnsincludes a tension of about 0 cN/tex.

Embodiment 32

The composite reinforcement of embodiment 3, wherein the tension of eachof the fiberglass yarns oriented in the cross direction includes atension of about 0 cN/tex.

Embodiment 33

The composite reinforcement or method of any one of embodiments 1, 2, 3,and 4, wherein the laid scrim includes a 0/90 laid scrim.

Embodiment 34

The composite reinforcement of any one of embodiments 1 and 2, whereinthe tension of at least some of the yarns in the second plurality ofyarns is configured to be relieved.

Embodiment 35

The composite reinforcement of embodiment 34, wherein the tension isconfigured to be relieved when the composite reinforcement is exposed totemperatures of at least approximately 35° C.

Embodiment 36

The composite reinforcement of embodiment 34, wherein the tension isconfigured to be relieved by shrinkage of the at least some of theyarns.

Embodiment 37

The composite reinforcement of embodiment 36, wherein the shrinkageoccurs in a direction parallel to the second direction.

Embodiment 38

The composite reinforcement of embodiment 36, wherein the shrinkageincludes a shortening of each of the at least some of the yarns in thesecond plurality of yarns.

Embodiment 39

The composite reinforcement of embodiment 38, wherein each of the atleast some of the yarns in the second plurality of yarns includes ashortening of at least between 0.2% and about 15%.

Embodiment 40

The composite reinforcement of embodiment 3, wherein the tension of eachof the polyester yarns oriented in the main direction is configured tobe relieved.

Embodiment 41

The composite reinforcement of embodiment 40, wherein the tension isconfigured to be relieved when the composite reinforcement is exposed totemperatures of at least approximately 35° C.

Embodiment 42

The composite reinforcement of embodiment 40, wherein the tension isconfigured to be relieved by shrinkage of each of the polyester yarns.

Embodiment 43

The composite reinforcement of embodiment 42, wherein the shrinkageoccurs in a direction parallel to the main direction.

Embodiment 44

The composite reinforcement of embodiment 42, wherein the shrinkageincludes a shortening of each of the polyester yarns.

Embodiment 45

The composite reinforcement of embodiment 44, wherein each of thepolyester yarns includes a shortening of at least between 0.2% and about15%.

Embodiment 46

The method of embodiment 4, further including forming the laid scrim.

Embodiment 47

The method of embodiment 46, wherein the second plurality of yarnsincludes a first group of yarns and a second group of yarns, whereinforming the laid scrim further includes laying the first plurality ofyarns between the first group of yarns and the second group of yarns.

Embodiment 48

The method of embodiment 46, wherein the tension is applied to each ofthe yarns in the second plurality of yarns while the laid scrim is beingformed.

Embodiment 49

The method of embodiment 4, wherein curing further includes setting thetension of each of the yarns in the second plurality of yarns.

Embodiment 50

The method of embodiment 4, wherein coating includes dip coating.

Embodiment 51

The method of embodiment 4, further including removing excess binderfrom the laid scrim before the laid scrim contacts the first nonwovenmat and the second nonwoven mat.

Embodiment 52

The method of embodiment 4, further including relieving the tension ofat least some of the yarns in the second plurality of yarns.

Embodiment 53

The method of embodiment 52, wherein the tension is relieved when thecomposite reinforcement is exposed to temperatures of at leastapproximately 35° C.

Embodiment 54

The method of embodiment 52, wherein the tension is configured to berelieved by shrinkage of the at least some of the yarns.

Embodiment 55

The method of embodiment 54, wherein the shrinkage occurs in a directionparallel to the second direction.

Embodiment 56

The method of embodiment 54, wherein the shrinkage includes a shorteningof each of the at least some of the yarns in the second plurality ofyarns.

Embodiment 57

The method of embodiment 56, wherein each of the at least some of theyarns in the second plurality of yarns includes a shortening of at leastbetween 0.2% and about 15%.

Embodiment 58

A method of preventing a distortion on a roofing surface, the methodincluding applying a roofing membrane to the roofing surface, theroofing membrane including a composite reinforcement, wherein thecomposite reinforcement includes: a first nonwoven mat, a laid scrimoverlying the first nonwoven mat, wherein the laid scrim includes afirst plurality of yarns substantially oriented in a first direction anda second plurality of yarns substantially oriented in a second directiondifferent from the first direction, wherein the second plurality ofyarns includes at least one different material from the first pluralityof yarns and wherein each of the yarns in the second plurality of yarnsincludes a tension greater than a tension of each of the yarns in thefirst plurality of yarns, a second nonwoven mat overlying the laidscrim, and a binder laminating the first nonwoven mat, the laid scrim,and the second nonwoven mat together to form the compositereinforcement, exposing the roofing membrane to an environmentalcondition, relieving the tension of at least some of the yarns in thesecond plurality of yarns in response to the environmental condition;and preventing the distortion on the roofing surface.

EXAMPLES

The following examples are provided to better disclose and teachprocesses and compositions of the present invention. They are forillustrative purposes only, and it must be acknowledged that minorvariations and changes can be made without materially affecting thespirit and scope of the invention as recited in the claims that follow.

Example 1

The scrims described herein can include shrinkable material to assist incounteracting the effects of dimensional expansion within a compositereinforcement. As also described herein (e.g., in FIG. 3), not only canthe amount of tension applied to a yarn made of shrinkable material betailored, the amount of future shrinkage experienced by the shrinkablematerial also can be predicted and tailored. The ability to predict andtailor future shrinkage of the scrim by tailoring the amount of tensionapplied to the shrinkable material in the scrim enables the scrim (andthe composite reinforcement) to be specifically designed to counteractdimensional expansion, and deformation, in particular geographicalsettings or environmental conditions.

Portions of two composite reinforcements were tested to analyze theeffect of different tensions on the expansion and contraction behaviorof the scrim. In a first composite reinforcement, a first plurality ofyarns of the scrim include fiberglass yarns and a second plurality ofyarns of the scrim include the shrinkable material of lower shrinkagepolyester yarns with a lower tension (e.g., approximately 4.5 cN/tex)applied to the shrinkable material (e.g., a lower tension applied toeach of the yarns). Sample A was taken from a portion of the firstcomposite reinforcement. In a second composite reinforcement, a firstplurality of yarns of the scrim include fiberglass yarns and a secondplurality of yarns of the scrim include the shrinkable material of thesame lower shrinkage polyester yarns, but a higher tension (e.g.,approximately 7.7 cN/tex) was applied to each of the yarns made of theshrinkable material. Sample B was taken from a portion of the secondcomposite reinforcement.

FIG. 5 depicts a graph of composite reinforcement displacement inaccordance with an embodiment described herein. For the first 15 minutesof the test, the Samples were heated. After 15 minutes, the heat wasremoved and the Samples returned to an ambient temperature. As theSamples were heated over the first 2-3 minutes of the test, each of theSamples experienced a positive displacement or dimensional expansion(e.g., lengthening of at least some of the yarns in the scrims) inresponse to the heat. When each of the Samples reached a maximumpositive displacement, the tendency of the shrinkable material to shrinkor contract in response to the dimensional expansion began to cause eachof the Samples to reduce their positive displacement. Sample Acontracted such that it had approximately no net displacement after 15minutes of heating, while Sample B contracted to a greater degree,leaving Sample B with a net negative displacement of approximately 10mils after 15 minutes of heating. Once the heat was removed at 15minutes, each of the Samples experienced further negative displacementas a result of the continued contraction of the shrinkable material, thereversible thermal expansion of the shrinkable material while cooling,and the cooling of the Sample. After 15 minutes of cooling (e.g., at 30minutes), Sample A exhibited a net negative displacement ofapproximately 10 mils, while Sample B exhibited a net negativedisplacement of approximately 20 mils. On average, Sample B (with thegreater tension applied to the shrinkable material), exhibitedapproximately 10 mils more shrinkage than Sample A. As such, the firstcomposite reinforcement from which Sample A was taken can be predictedto exhibit less shrinkage or contraction, which behavior may bedesirable in certain instances or applications. For example, thiscomposite reinforcement may be useful in a cold adhesive application,where products should desirably exhibit complete compensation for athermal expansion after approximately 15 minutes of exposure to a heatsource. As shown in FIG. 5, the thermal expansion experienced by SampleA was desirably reversed after 15 minutes of heating. The secondcomposite reinforcement, from which Sample B was taken, can be predictedto exhibit more shrinkage or contraction, which behavior may bedesirable in other instances or applications. Therefore, by tailoring inadvance the tension applied to the shrinkable material, the futureshrinkage behavior of the scrim can be predicted, which can enable thescrim (and the composite reinforcement) to be specifically designed tocounteract dimensional expansion, and deformation, in particulargeographical settings or environmental conditions. In contrast, aconventional reinforcement that does not contain a second plurality ofyarns under tension will nevertheless have thermal expansion during thefirst 15 minutes of exposure to the thermal condition and providedefects that remain as a positive displacement, or elongation, of atleast about 20 mil.

Example 2

The composite reinforcements described herein are configured to beincorporated into other structures. For example, when used to create aroofing membrane, the composite reinforcement is impregnated (e.g.,permeated) with an asphaltic composition, such as an asphaltic rubbercomposition. The manner and location(s) in which the binder isdistributed within one or more layers of the composite reinforcement,however, can maximize the air permeability of that layer, which in turnleads to an increased ability to permeate the reinforcement withasphalt.

FIG. 6 depicts a graph of composite reinforcement air permeability inaccordance with an embodiment described herein. Air permeability ismeasured to assess how well the composite reinforcement can beimpregnated by an asphaltic composition. Higher air permeabilityindicates that the composite reinforcement is more likely to be fullyimpregnated by the asphaltic composition. Successful impregnation of thelayers in the composite reinforcement by the asphaltic composition canlead to greater interlaminar strength within the reinforcement (e.g.,less delamination between the layers of the composite reinforcement) andincreased peel strength of the resulting roofing membrane. Sample X wastaken from a composite reinforcement that was coated with a binder inaccordance with the unsaturated method or technique described herein.Sample Y was taken from a composite reinforcement that was coated inaccordance with the saturated method or technique described herein. Theair permeability of both Samples was obtained in units of cubic feet ofair per minute per square foot (CFM). The air permeability of Sample Xwas 316 CFM, while the air permeability of Sample Y was 259 CFM. Greaterair permeability in Sample X indicates that a composite reinforcementcoated with binder by the unsaturated coating technique desirably can bemore fully permeated by an asphaltic composition than a compositereinforcement coated by the saturated coating technique.

The composite reinforcement of the present invention represents adeparture from and improvement over conventional reinforcements,particularly for roofing applications. Conventional reinforcements areprone to “mole running,” or dimensional expansion along the length ofthe reinforcement, which can cause deformation of the reinforcement atone or more points where the roofing membrane is weakly adhered to theroof. Conventional reinforcements also are prone to “dog legging,” orskewing of an otherwise balanced fabric. By contrast, the compositereinforcement of the present invention can be tailored to avoid both ofthese phenomena. Through proper selection of one or more shrinkablematerials (depending on the specific conditions to which the compositereinforcement will be exposed) and proper treatment of those materialsduring manufacturing (e.g., by the variable application of tensionand/or heat to the materials), the composite reinforcement describedherein can resist skewing of layers within the reinforcement and overalldeformation of the reinforcement.

Certain features, for clarity, described herein in the context ofseparate embodiments, may also be provided in combination in a singleembodiment. Conversely, various features that are, for brevity,described in the context of a single embodiment, may also be providedseparately or in any subcombination. Further, reference to values statedin ranges includes each and every value within that range.

Benefits, other advantages, and solutions to problems have beendescribed above with regard to specific embodiments. However, thebenefits, advantages, solutions to problems, and any feature(s) that maycause any benefit, advantage, or solution to occur or become morepronounced are not to be construed as a critical, required, or essentialfeature of any or all the claims.

The specification and illustrations of the embodiments described hereinare intended to provide a general understanding of the structure of thevarious embodiments. The specification and illustrations are notintended to serve as an exhaustive and comprehensive description of allof the elements and features of apparatus and systems that use thestructures or methods described herein. Separate embodiments may also beprovided in combination in a single embodiment, and conversely, variousfeatures that are, for brevity, described in the context of a singleembodiment, may also be provided separately or in any subcombination.Further, reference to values stated in ranges includes each and everyvalue within that range. Many other embodiments may be apparent toskilled artisans only after reading this specification. Otherembodiments may be used and derived from the disclosure, such that astructural substitution, logical substitution, or another change may bemade without departing from the scope of the disclosure. Accordingly,the disclosure is to be regarded as illustrative rather thanrestrictive.

What is claimed is:
 1. A composite reinforcement comprising: a firstnonwoven mat; a laid scrim overlying the first nonwoven mat, wherein thelaid scrim comprises a first plurality of yarns substantially orientedin a first direction and a second plurality of yarns substantiallyoriented in a second direction different from the first direction,wherein the second plurality of yarns comprises at least one differentmaterial from the first plurality of yarns and wherein each of the yarnsin the second plurality of yarns comprises a tension greater than atension of each of the yarns in the first plurality of yarns; a secondnonwoven mat overlying the laid scrim; and a binder laminating the firstnonwoven mat, the laid scrim, and the second nonwoven mat together toform the composite reinforcement.
 2. The composite reinforcement ofclaim 1, wherein the first nonwoven mat comprises polyester fibers. 3.The composite reinforcement of claim 1, wherein the second nonwoven matcomprises fiberglass fibers.
 4. The composite reinforcement of claim 1,wherein the first plurality of yarns comprises fiberglass yarns.
 5. Thecomposite reinforcement of claim 1, wherein the second plurality ofyarns comprises polyester yarns and fiberglass yarns.
 6. The compositereinforcement of claim 1, wherein the first direction is a crossdirection of the laid scrim and the second direction is a main directionof the laid scrim, and wherein the first plurality of yarns issubstantially oriented in the cross direction and wherein the secondplurality of yarns is substantially oriented in the main direction. 7.The composite reinforcement of claim 1, wherein the binder penetrates atleast a portion of the second nonwoven mat without saturating the secondnonwoven mat.
 8. The composite reinforcement of claim 1, wherein thelaid scrim comprises a greater concentration of binder than the firstnonwoven mat or the second nonwoven mat.
 9. The composite reinforcementof claim 1, wherein the tension of each of the yarns of the secondplurality of yarns comprises a tension between about 1.0 cN/tex andabout 18 cN/tex.
 10. The composite reinforcement of claim 1, wherein thetension of at least some of the yarns in the second plurality of yarnsis configured to be relieved by shrinkage of the at least some of theyarns, wherein the shrinkage occurs in a direction parallel to thesecond direction.
 11. The composite reinforcement of claim 10, whereinthe shrinkage comprises a shortening of each of the at least some of theyarns in the second plurality of yarns, wherein the shortening comprisesat least between 0.2% and about 15%.
 12. A composite reinforcementconfigured for incorporation into a roofing membrane, wherein thecomposite reinforcement comprises: a polyester nonwoven mat; a laidscrim overlying the polyester nonwoven mat, wherein the laid scrimcomprises a plurality of fiberglass yarns oriented in a cross directionof the laid scrim and a plurality of polyester yarns and fiberglassyarns oriented in a main direction of the laid scrim, and wherein eachof the polyester yarns and fiberglass yarns oriented in the maindirection comprises a tension greater than a tension of each of thefiberglass yarns oriented in the cross direction; a fiberglass nonwovenmat overlying the laid scrim; and a binder laminating the polyesternonwoven mat, the laid scrim, and the fiberglass nonwoven mat togetherto form the composite reinforcement.
 13. A method of forming a compositereinforcement, the method comprising: coating a laid scrim with abinder, wherein the laid scrim comprises a first plurality of yarnssubstantially oriented in a first direction and a second plurality ofyarns substantially oriented in a second direction different from thefirst direction, wherein the second plurality of yarns comprises atleast one different material from the first plurality of yarns andwherein each of the yarns in the second plurality of yarns comprises atension greater than a tension of each of the yarns in the firstplurality of yarns; contacting the laid scrim with a first nonwoven matand a second nonwoven mat, wherein the laid scrim overlies the firstnonwoven mat and wherein the second nonwoven mat overlies the laidscrim; and curing the binder to form the composite reinforcement. 14.The method of claim 13, further comprising relieving the tension of atleast some of the yarns in the second plurality of yarns, wherein thetension is configured to be relieved by shrinkage of the at least someof the yarns, wherein the shrinkage occurs in a direction parallel tothe second direction.
 15. The method of claim 14, wherein the shrinkagecomprises a shortening of each of the at least some of the yarns in thesecond plurality of yarns, wherein the shortening comprises at leastbetween 0.2% and about 15%.